Develop Reference

Crashlytics class not recognized with Firebase Crashlytics SDK

With the Firebase Crashlytics SDK, the documentation explains how you can
force a crash
However, in the line:
Crashlytics.getInstance().crash();
Crashlytics is unrecognized and cannot be imported.
I tried switching to FirebaseCrashlytics.getInstance() but there is no crash() method.
Note: Crashlytics is indeed set up properly - I am able to cause my own crash by looking up a view that does not exist and it is reported correctly.

We have deprecated the force crash method in the new SDK. One example of a way to force a crash is manually throwing an exception
throw new RuntimeException("This is a crash");

Warning: can't find referenced method 'int save(int)' in library class android.graphics.Canvas

I'm using a no-longer maintained Umano's AndroidSlidingUpPanel library in one of my applications:
dependencies {
// .. redacted
implementation 'com.sothree.slidinguppanel:library:3.4.0'
}
Everything worked fine till now. Today I've tried to change the compileSdkVersion from 27 to 28, and the release build started to fail with a Proguard error (minifyEnabled set to true):
$ ./gradlew clean assembleRelease
> Task :app:transformClassesAndResourcesWithProguardForRelease FAILED
ProGuard, version 6.0.3
Reading input...
// many lines with 'Reading program jar...', redacted
Initializing...
Warning: com.sothree.slidinguppanel.SlidingUpPanelLayout: can't find referenced method 'int save(int)' in library class android.graphics.Canvas
// redacted
Warning: there were 1 unresolved references to library class members.
You probably need to update the library versions.
(http://proguard.sourceforge.net/manual/troubleshooting.html#unresolvedlibraryclassmember)
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:transformClassesAndResourcesWithProguardForRelease'.
> java.io.IOException: Please correct the above warnings first.
BUILD FAILED in 2s
I'm using AGP v3.5.0, with android.enableR8=false configuration to favor Proguard over R8.
One of the comments in this issue suggests to ignore the warning using -dontwarn com.sothree.**, which indeed causes the build to pass.
Why this warning started to appear in the first place, and are there any possible ramifications for ignoring it?

Let's analyze the warning message:
Warning: com.sothree.slidinguppanel.SlidingUpPanelLayout: can't find
referenced method 'int save(int)' in library class
android.graphics.Canvas
Library's SlidingUpPanelLayout.java source file indeed includes a android.graphics.Canvas#save(int) method invocation:
final int save = canvas.save(Canvas.CLIP_SAVE_FLAG);
This method is deprecated since API 26, and was marked as #removed in API 28.
The #removed annotation (along with #hide annotation) is being used by doclava tool (AOSP tool which generates public framework API stub, a.k.a. android.jar) to mark public class methods as hidden.
To summarize: the android.graphics.Canvas#save(int) method was removed from the public API, but it is still part of the runtime/framework (see also this). During minification stage Proguard analyzes the bytecode and obviously fails to find the not-anymore-public-api android.graphics.Canvas#save(int) method and displays the above warning.
This method is still present in runtime, therefore Proguard warning can be ignored given two caveats:
Since this method is not part of public API anymore, a particular vendor might alter the framework classes (i.e., by renaming/removing this method) in a way which will cause runtime errors.
This method might be removed in future AOSP version, and you probably won't notice that till this method will be called on affected device.
The warning ignore rule can be narrowed to:
-dontwarn com.sothree.slidinguppanel.SlidingUpPanelLayout
In a long run, I'd suggest to consider patching this library by yourself (by changing the functionality to use the parameterless android.graphics.Canvas#save() method), or if that's not possible - migrate to another solution.

How do i resolve this warning junit5 throws when i run Parameterized tests?

I get this warning in my test console when i run test cases annotated with #ParameterizedTest
"org.junit.platform.launcher.core.InternalTestPlan add
WARNING: Attempt to modify the TestPlan was detected. A future version of the JUnit Platform will ignore this call and eventually even throw an exception. Please contact your IDE/tool vendor and request a fix (see https://github.com/junit-team/junit5/issues/1732 for details)."
How do i fix it?

According to the link in the error message, it would seem that:
IntelliJ IDEA is affected, fix is on its way: JetBrains/intellij-community#1030
Following that link, it seems that it should be fixed in the 2019.1 release of IntelliJ.

Is Android Gradle Plugin test apk builder automatically multidexing my test apk? If so, why is this generating "NoSuchMethodError"

This all started with this error when running instrumentation tests:
java.lang.NoSuchMethodError: No static method closeQuietly(Ljava/net/ServerSocket;)V in class Lokhttp3/internal/Util; or its super classes (declaration of 'okhttp3.internal.Util' appears in /data/app/com.example-vKdPJoTLl49ntRbZfsRBqQ==/base.apk!classes2.dex)
at okhttp3.mockwebserver.MockWebServer$2.execute(MockWebServer.java:333)
at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:32)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
at java.lang.Thread.run(Thread.java:764)
I went looking into the generated test.apk to see what was present/missing in dex files.
First thing I noticed is that the test apk has two .dex files. Why? I'm not using multidex (and IIRC multidex doesn't work on test apks anyways). I then added up the two "referenced method counts" and sure enough I'm over the 65k limit. So is AGP auto-multi-dexing my test apk?
Furthermore I see the "missing" method in the first dex.
Why is it listed as a "reference" not a "defined" method? It's not like there is an OkHttp Util class provided by the framework.
In the initial crash, it said it can't find method in classes2.dex. Why is it looking in classes2.dex? Why not look in both?
I'm keeping everything in my test apk (using proguard but keeping everything) (maybe this explains the +65k ref methods). So why is this getting stripped/screwed with in the first place.
UPDATE:
It turns out this method was needed in my app .apk (not the test .apk). When I updated my proguard rules for the app apk everything worked. I still don't know why this class is needed in-app?

java.lang.NoSuchMethodError:
No static method closeQuietly(java.net.ServerSocket) in class okhttp3.internal.Util;
method closeQuietly(java.net.ServerSocket) might not be in use.
to explicitly keep it:
-keep class okhttp3.internal.Util {
public static void closeQuietly(java.net.ServerSocket);
}

I don't know how I didn't know this but apparently multidex is enabled by default on API 21+
https://developer.android.com/studio/build/multidex#mdex-on-l
Therefore, if your minSdkVersion is 21 or higher multidex is enabled
by default, and you do not need the multidex support library.
So yeah, this is normal. What might be happening is that the class is just not in the first dex file.

Mocking Google Analytics v4

I'm trying to test my code that depends on Google Analytics SDK v4.
Specifically I'm trying to mock com.google.android.gms.analytics.Tracker with Mockito.
Tracker tracker = Mockito.mock(Tracker.class); yields this error.
Are there any approaches to take? The only thing I can think of is to create my own wrapper.

I believe the code snipped at fault is Tracker.class - as this will instantiate the class, which in turn throws the VerifyError. This is not an issue with your code, but is a limitation of Google Play Services. The issue has been reported in the Robolectric project and here.
I used the solution provided in the second link by SuperJugy, by inserting the following to the bottom of my Gradle build file:
tasks.withType(Test) {
test {
// set JVM arguments for the test JVM(s)
jvmArgs '-XX:-UseSplitVerifier'
}
}
To get it working in Android Studio I had to add the VM Option -noverify to my test build configuration.
I think you may be able to work-around the problem using a wrapper, so long as the wrapper code never instantiates the Tracker class. However this may not be easy (or possible?), please let me know if end up going down this path and succeed!